[Cytotoxic effect of HepG2 cell expressing CD95L in an autocrine and paracrine way].

OBJECTIVE: The clearance of HBV-infected hepatocyte is mainly mediated by the CTL expressing CD95L. We have found that the hepatocytes also express CD95L in hepatitis B, a molecule with cytotoxic effect. This study was to elucidate its effect mechanism. METHODS: The HepG2 cell was induced to express CD95L and coincubated with HepG2.2.15 cell. The supernate from the induced HepG2 cell culture was added to another untreated HepG2 fraction. The apoptosis rates were examined with flow cytometry. The apoptosis of individual HepG2 cell incubation was also examined. RESULTS: The HepG2 cell expressing CD95L was able to kill the HepG2.2.15 cell with CD95 expression, apoptotic rates were 16.5% at 24 h and 43.0% at 48 h incubation. The supernate induced apoptosis rates of 38.7% and 73.3%, and the suicide rates of individual HepG2 cell incubation were 43.8% at 24 h. All these data were higher than those in controls. The apoptosis could be blocked with addition of anti-CD95L monoclonal antibody. CONCLUSION: The HepG2 cell expressing CD95L mediated cytotoxic effect by an autocrine and paracrine mechanism.